D-Glucosamine

D-Glucosamine is a monosaccharide that contains an amine group in place of one of the hydroxyl groups. Like most saccharides, it exists mostly in a cyclic configuration (the α-form is shown here) rather than as its linear form.

Only the D-enantiomer of glucosamine exists in nature. It is found in chitin (a cellulose-like polymer of N-acetylglucosamine), mucoproteins (proteins with >4% carbohydrate content), and mucopolysaccharides (polysaccharides that contain repeating amino sugar/non-amino sugar disaccharides).

Georg Ledderhose, a medical student at Strasbourg University (then in Germany), isolated glucosamine from cartilage-derived chitin in 1876 and named it glycosamin. Chemist Emil Fischer and his student Hermann Leuchs at the University of Berlin first reported its synthesis in 1902 (the same year that Fischer was awarded the Nobel Prize in Chemistry).

Glucosamine, as its sulfate salt and often in combination with the polydisaccharide chondroitin, is marketed over-the-counter as a treatment for osteoarthritis inflammation and its accompanying pain. Despite numerous clinical trials, however, there is little evidence that it is effective for this or any other malady. As a result, the US Federal Drug Administration has not approved glucosamine for medical use. FDA has sued at least two drug companies for making false claims about their glucosamine products.

By 2003, many European countries had approved glucosamine salts as safe, effective treatments for managing arthritis pain. But in 2009, the European Food Safety Authority (EFSA), responding to a request from the European Commission, stated, “A cause and effect relationship has not been established between the consumption of glucosamine [salts] . . . and the maintenance of normal joints.”

The report added, “A cause and effect relationship has not been established between the dietary intake of glucosamine [sulfate] and reduction of inflammation in the general population.”